includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  *
   5  * @package MediaWiki
   6  */
   7
   8 /** */
   9 require_once( 'normal/UtfNormal.php' );
  10
  11 $wgTitleInterwikiCache = array();
  12 $wgTitleCache = array();
  13
  14 define ( 'GAID_FOR_UPDATE', 1 );
  15
  16 # Title::newFromTitle maintains a cache to avoid
  17 # expensive re-normalization of commonly used titles.
  18 # On a batch operation this can become a memory leak
  19 # if not bounded. After hitting this many titles,
  20 # reset the cache.
  21 define( 'MW_TITLECACHE_MAX', 1000 );
  22
  23 /**
  24  * Title class
  25  * - Represents a title, which may contain an interwiki designation or namespace
  26  * - Can fetch various kinds of data from the database, albeit inefficiently.
  27  *
  28  * @package MediaWiki
  29  */
  30 class Title {
  31         /**
  32          * All member variables should be considered private
  33          * Please use the accessor functions
  34          */
  35
  36          /**#@+
  37          * @access private
  38          */
  39
  40         var $mTextform;           # Text form (spaces not underscores) of the main part
  41         var $mUrlform;            # URL-encoded form of the main part
  42         var $mDbkeyform;          # Main part with underscores
  43         var $mNamespace;          # Namespace index, i.e. one of the NS_xxxx constants
  44         var $mInterwiki;          # Interwiki prefix (or null string)
  45         var $mFragment;           # Title fragment (i.e. the bit after the #)
  46         var $mArticleID;          # Article ID, fetched from the link cache on demand
  47         var $mLatestID;         # ID of most recent revision
  48         var $mRestrictions;       # Array of groups allowed to edit this article
  49                               # Only null or "sysop" are supported
  50         var $mRestrictionsLoaded; # Boolean for initialisation on demand
  51         var $mPrefixedText;       # Text form including namespace/interwiki, initialised on demand
  52         var $mDefaultNamespace;   # Namespace index when there is no namespace
  53                               # Zero except in {{transclusion}} tags
  54         var $mWatched;            # Is $wgUser watching this page? NULL if unfilled, accessed through userIsWatching()
  55         /**#@-*/
  56
  57
  58         /**
  59          * Constructor
  60          * @access private
  61          */
  62         /* private */ function Title() {
  63                 $this->mInterwiki = $this->mUrlform =
  64                 $this->mTextform = $this->mDbkeyform = '';
  65                 $this->mArticleID = -1;
  66                 $this->mNamespace = NS_MAIN;
  67                 $this->mRestrictionsLoaded = false;
  68                 $this->mRestrictions = array();
  69                 # Dont change the following, NS_MAIN is hardcoded in several place
  70                 # See bug #696
  71                 $this->mDefaultNamespace = NS_MAIN;
  72                 $this->mWatched = NULL;
  73                 $this->mLatestID = false;
  74         }
  75
  76         /**
  77          * Create a new Title from a prefixed DB key
  78          * @param string $key The database key, which has underscores
  79          *      instead of spaces, possibly including namespace and
  80          *      interwiki prefixes
  81          * @return Title the new object, or NULL on an error
  82          * @static
  83          * @access public
  84          */
  85         /* static */ function newFromDBkey( $key ) {
  86                 $t = new Title();
  87                 $t->mDbkeyform = $key;
  88                 if( $t->secureAndSplit() )
  89                         return $t;
  90                 else
  91                         return NULL;
  92         }
  93
  94         /**
  95          * Create a new Title from text, such as what one would
  96          * find in a link. Decodes any HTML entities in the text.
  97          *
  98          * @param string $text the link text; spaces, prefixes,
  99          *      and an initial ':' indicating the main namespace
 100          *      are accepted
 101          * @param int $defaultNamespace the namespace to use if
 102          *      none is specified by a prefix
 103          * @return Title the new object, or NULL on an error
 104          * @static
 105          * @access public
 106          */
 107         function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 108                 global $wgTitleCache;
 109                 $fname = 'Title::newFromText';
 110
 111                 if( is_object( $text ) ) {
 112                         wfDebugDieBacktrace( 'Title::newFromText given an object' );
 113                 }
 114
 115                 /**
 116                  * Wiki pages often contain multiple links to the same page.
 117                  * Title normalization and parsing can become expensive on
 118                  * pages with many links, so we can save a little time by
 119                  * caching them.
 120                  *
 121                  * In theory these are value objects and won't get changed...
 122                  */
 123                 if( $defaultNamespace == NS_MAIN && isset( $wgTitleCache[$text] ) ) {
 124                         return $wgTitleCache[$text];
 125                 }
 126
 127                 /**
 128                  * Convert things like &eacute; &#257; or &#x3017; into real text...
 129                  */
 130                 $filteredText = Sanitizer::decodeCharReferences( $text );
 131
 132                 $t =& new Title();
 133                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 134                 $t->mDefaultNamespace = $defaultNamespace;
 135
 136                 static $cachedcount = 0 ;
 137                 if( $t->secureAndSplit() ) {
 138                         if( $defaultNamespace == NS_MAIN ) {
 139                                 if( $cachedcount >= MW_TITLECACHE_MAX ) {
 140                                         # Avoid memory leaks on mass operations...
 141                                         $wgTitleCache = array();
 142                                         $cachedcount=0;
 143                                 }
 144                                 $cachedcount++;
 145                                 $wgTitleCache[$text] =& $t;
 146                         }
 147                         return $t;
 148                 } else {
 149                         $ret = NULL;
 150                         return $ret;
 151                 }
 152         }
 153
 154         /**
 155          * Create a new Title from URL-encoded text. Ensures that
 156          * the given title's length does not exceed the maximum.
 157          * @param string $url the title, as might be taken from a URL
 158          * @return Title the new object, or NULL on an error
 159          * @static
 160          * @access public
 161          */
 162         function newFromURL( $url ) {
 163                 global $wgLegalTitleChars;
 164                 $t = new Title();
 165
 166                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 167                 # but some URLs used it as a space replacement and they still come
 168                 # from some external search tools.
 169                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 170                         $url = str_replace( '+', ' ', $url );
 171                 }
 172
 173                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 174                 if( $t->secureAndSplit() ) {
 175                         return $t;
 176                 } else {
 177                         return NULL;
 178                 }
 179         }
 180
 181         /**
 182          * Create a new Title from an article ID
 183          *
 184          * @todo This is inefficiently implemented, the page row is requested
 185          *       but not used for anything else
 186          *
 187          * @param int $id the page_id corresponding to the Title to create
 188          * @return Title the new object, or NULL on an error
 189          * @access public
 190          * @static
 191          */
 192         function newFromID( $id ) {
 193                 $fname = 'Title::newFromID';
 194                 $dbr =& wfGetDB( DB_SLAVE );
 195                 $row = $dbr->selectRow( 'page', array( 'page_namespace', 'page_title' ),
 196                         array( 'page_id' => $id ), $fname );
 197                 if ( $row !== false ) {
 198                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
 199                 } else {
 200                         $title = NULL;
 201                 }
 202                 return $title;
 203         }
 204
 205         /**
 206          * Create a new Title from a namespace index and a DB key.
 207          * It's assumed that $ns and $title are *valid*, for instance when
 208          * they came directly from the database or a special page name.
 209          * For convenience, spaces are converted to underscores so that
 210          * eg user_text fields can be used directly.
 211          *
 212          * @param int $ns the namespace of the article
 213          * @param string $title the unprefixed database key form
 214          * @return Title the new object
 215          * @static
 216          * @access public
 217          */
 218         function &makeTitle( $ns, $title ) {
 219                 $t =& new Title();
 220                 $t->mInterwiki = '';
 221                 $t->mFragment = '';
 222                 $t->mNamespace = intval( $ns );
 223                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 224                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 225                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 226                 $t->mTextform = str_replace( '_', ' ', $title );
 227                 return $t;
 228         }
 229
 230         /**
 231          * Create a new Title frrom a namespace index and a DB key.
 232          * The parameters will be checked for validity, which is a bit slower
 233          * than makeTitle() but safer for user-provided data.
 234          *
 235          * @param int $ns the namespace of the article
 236          * @param string $title the database key form
 237          * @return Title the new object, or NULL on an error
 238          * @static
 239          * @access public
 240          */
 241         function makeTitleSafe( $ns, $title ) {
 242                 $t = new Title();
 243                 $t->mDbkeyform = Title::makeName( $ns, $title );
 244                 if( $t->secureAndSplit() ) {
 245                         return $t;
 246                 } else {
 247                         return NULL;
 248                 }
 249         }
 250
 251         /**
 252          * Create a new Title for the Main Page
 253          *
 254          * @static
 255          * @return Title the new object
 256          * @access public
 257          */
 258         function newMainPage() {
 259                 return Title::newFromText( wfMsgForContent( 'mainpage' ) );
 260         }
 261
 262         /**
 263          * Create a new Title for a redirect
 264          * @param string $text the redirect title text
 265          * @return Title the new object, or NULL if the text is not a
 266          *      valid redirect
 267          * @static
 268          * @access public
 269          */
 270         function newFromRedirect( $text ) {
 271                 global $wgMwRedir;
 272                 $rt = NULL;
 273                 if ( $wgMwRedir->matchStart( $text ) ) {
 274                         if ( preg_match( '/\[{2}(.*?)(?:\||\]{2})/', $text, $m ) ) {
 275                                 # categories are escaped using : for example one can enter:
 276                                 # #REDIRECT [[:Category:Music]]. Need to remove it.
 277                                 if ( substr($m[1],0,1) == ':') {
 278                                         # We don't want to keep the ':'
 279                                         $m[1] = substr( $m[1], 1 );
 280                                 }
 281
 282                                 $rt = Title::newFromText( $m[1] );
 283                                 # Disallow redirects to Special:Userlogout
 284                                 if ( !is_null($rt) && $rt->getNamespace() == NS_SPECIAL && preg_match( '/^Userlogout/i', $rt->getText() ) ) {
 285                                         $rt = NULL;
 286                                 }
 287                         }
 288                 }
 289                 return $rt;
 290         }
 291
 292 #----------------------------------------------------------------------------
 293 #       Static functions
 294 #----------------------------------------------------------------------------
 295
 296         /**
 297          * Get the prefixed DB key associated with an ID
 298          * @param int $id the page_id of the article
 299          * @return Title an object representing the article, or NULL
 300          *      if no such article was found
 301          * @static
 302          * @access public
 303          */
 304         function nameOf( $id ) {
 305                 $fname = 'Title::nameOf';
 306                 $dbr =& wfGetDB( DB_SLAVE );
 307
 308                 $s = $dbr->selectRow( 'page', array( 'page_namespace','page_title' ),  array( 'page_id' => $id ), $fname );
 309                 if ( $s === false ) { return NULL; }
 310
 311                 $n = Title::makeName( $s->page_namespace, $s->page_title );
 312                 return $n;
 313         }
 314
 315         /**
 316          * Get a regex character class describing the legal characters in a link
 317          * @return string the list of characters, not delimited
 318          * @static
 319          * @access public
 320          */
 321         function legalChars() {
 322                 global $wgLegalTitleChars;
 323                 return $wgLegalTitleChars;
 324         }
 325
 326         /**
 327          * Get a string representation of a title suitable for
 328          * including in a search index
 329          *
 330          * @param int $ns a namespace index
 331          * @param string $title text-form main part
 332          * @return string a stripped-down title string ready for the
 333          *      search index
 334          */
 335         /* static */ function indexTitle( $ns, $title ) {
 336                 global $wgContLang;
 337                 require_once( 'SearchEngine.php' );
 338
 339                 $lc = SearchEngine::legalSearchChars() . '&#;';
 340                 $t = $wgContLang->stripForSearch( $title );
 341                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 342                 $t = strtolower( $t );
 343
 344                 # Handle 's, s'
 345                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 346                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 347
 348                 $t = preg_replace( "/\\s+/", ' ', $t );
 349
 350                 if ( $ns == NS_IMAGE ) {
 351                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 352                 }
 353                 return trim( $t );
 354         }
 355
 356         /*
 357          * Make a prefixed DB key from a DB key and a namespace index
 358          * @param int $ns numerical representation of the namespace
 359          * @param string $title the DB key form the title
 360          * @return string the prefixed form of the title
 361          */
 362         /* static */ function makeName( $ns, $title ) {
 363                 global $wgContLang;
 364
 365                 $n = $wgContLang->getNsText( $ns );
 366                 return $n == '' ? $title : "$n:$title";
 367         }
 368
 369         /**
 370          * Returns the URL associated with an interwiki prefix
 371          * @param string $key the interwiki prefix (e.g. "MeatBall")
 372          * @return the associated URL, containing "$1", which should be
 373          *      replaced by an article title
 374          * @static (arguably)
 375          * @access public
 376          */
 377         function getInterwikiLink( $key )  {
 378                 global $wgMemc, $wgDBname, $wgInterwikiExpiry, $wgTitleInterwikiCache;
 379                 global $wgInterwikiCache;
 380                 $fname = 'Title::getInterwikiLink';
 381
 382                 $key = strtolower( $key );
 383
 384                 $k = $wgDBname.':interwiki:'.$key;
 385                 if( array_key_exists( $k, $wgTitleInterwikiCache ) ) {
 386                         return $wgTitleInterwikiCache[$k]->iw_url;
 387                 }
 388
 389                 if ($wgInterwikiCache) {
 390                         return Title::getInterwikiCached( $key );
 391                 }
 392
 393                 $s = $wgMemc->get( $k );
 394                 # Ignore old keys with no iw_local
 395                 if( $s && isset( $s->iw_local ) && isset($s->iw_trans)) {
 396                         $wgTitleInterwikiCache[$k] = $s;
 397                         return $s->iw_url;
 398                 }
 399
 400                 $dbr =& wfGetDB( DB_SLAVE );
 401                 $res = $dbr->select( 'interwiki',
 402                         array( 'iw_url', 'iw_local', 'iw_trans' ),
 403                         array( 'iw_prefix' => $key ), $fname );
 404                 if( !$res ) {
 405                         return '';
 406                 }
 407
 408                 $s = $dbr->fetchObject( $res );
 409                 if( !$s ) {
 410                         # Cache non-existence: create a blank object and save it to memcached
 411                         $s = (object)false;
 412                         $s->iw_url = '';
 413                         $s->iw_local = 0;
 414                         $s->iw_trans = 0;
 415                 }
 416                 $wgMemc->set( $k, $s, $wgInterwikiExpiry );
 417                 $wgTitleInterwikiCache[$k] = $s;
 418
 419                 return $s->iw_url;
 420         }
 421
 422         /**
 423          * Fetch interwiki prefix data from local cache in constant database
 424          *
 425          * More logic is explained in DefaultSettings
 426          *
 427          * @return string URL of interwiki site
 428          * @access public
 429          */
 430         function getInterwikiCached( $key ) {
 431                 global $wgDBname, $wgInterwikiCache, $wgInterwikiScopes, $wgInterwikiFallbackSite;
 432                 global $wgTitleInterwikiCache;
 433                 static $db, $site;
 434
 435                 if (!$db)
 436                         $db=dba_open($wgInterwikiCache,'r','cdb');
 437                 /* Resolve site name */
 438                 if ($wgInterwikiScopes>=3 and !$site) {
 439                         $site = dba_fetch("__sites:{$wgDBname}", $db);
 440                         if ($site=="")
 441                                 $site = $wgInterwikiFallbackSite;
 442                 }
 443                 $value = dba_fetch("{$wgDBname}:{$key}", $db);
 444                 if ($value=='' and $wgInterwikiScopes>=3) {
 445                         /* try site-level */
 446                         $value = dba_fetch("_{$site}:{$key}", $db);
 447                 }
 448                 if ($value=='' and $wgInterwikiScopes>=2) {
 449                         /* try globals */
 450                         $value = dba_fetch("__global:{$key}", $db);
 451                 }
 452                 if ($value=='undef')
 453                         $value='';
 454                 $s = (object)false;
 455                 $s->iw_url = '';
 456                 $s->iw_local = 0;
 457                 $s->iw_trans = 0;
 458                 if ($value!='') {
 459                         list($local,$url)=explode(' ',$value,2);
 460                         $s->iw_url=$url;
 461                         $s->iw_local=(int)$local;
 462                 }
 463                 $wgTitleInterwikiCache[$wgDBname.':interwiki:'.$key] = $s;
 464                 return $s->iw_url;
 465         }
 466         /**
 467          * Determine whether the object refers to a page within
 468          * this project.
 469          *
 470          * @return bool TRUE if this is an in-project interwiki link
 471          *      or a wikilink, FALSE otherwise
 472          * @access public
 473          */
 474         function isLocal() {
 475                 global $wgTitleInterwikiCache, $wgDBname;
 476
 477                 if ( $this->mInterwiki != '' ) {
 478                         # Make sure key is loaded into cache
 479                         $this->getInterwikiLink( $this->mInterwiki );
 480                         $k = $wgDBname.':interwiki:' . $this->mInterwiki;
 481                         return (bool)($wgTitleInterwikiCache[$k]->iw_local);
 482                 } else {
 483                         return true;
 484                 }
 485         }
 486
 487         /**
 488          * Determine whether the object refers to a page within
 489          * this project and is transcludable.
 490          *
 491          * @return bool TRUE if this is transcludable
 492          * @access public
 493          */
 494         function isTrans() {
 495                 global $wgTitleInterwikiCache, $wgDBname;
 496
 497                 if ($this->mInterwiki == '')
 498                         return false;
 499                 # Make sure key is loaded into cache
 500                 $this->getInterwikiLink( $this->mInterwiki );
 501                 $k = $wgDBname.':interwiki:' . $this->mInterwiki;
 502                 return (bool)($wgTitleInterwikiCache[$k]->iw_trans);
 503         }
 504
 505         /**
 506          * Update the page_touched field for an array of title objects
 507          * @todo Inefficient unless the IDs are already loaded into the
 508          *      link cache
 509          * @param array $titles an array of Title objects to be touched
 510          * @param string $timestamp the timestamp to use instead of the
 511          *      default current time
 512          * @static
 513          * @access public
 514          */
 515         function touchArray( $titles, $timestamp = '' ) {
 516
 517                 if ( count( $titles ) == 0 ) {
 518                         return;
 519                 }
 520                 $dbw =& wfGetDB( DB_MASTER );
 521                 if ( $timestamp == '' ) {
 522                         $timestamp = $dbw->timestamp();
 523                 }
 524                 /*
 525                 $page = $dbw->tableName( 'page' );
 526                 $sql = "UPDATE $page SET page_touched='{$timestamp}' WHERE page_id IN (";
 527                 $first = true;
 528
 529                 foreach ( $titles as $title ) {
 530                         if ( $wgUseFileCache ) {
 531                                 $cm = new CacheManager($title);
 532                                 @unlink($cm->fileCacheName());
 533                         }
 534
 535                         if ( ! $first ) {
 536                                 $sql .= ',';
 537                         }
 538                         $first = false;
 539                         $sql .= $title->getArticleID();
 540                 }
 541                 $sql .= ')';
 542                 if ( ! $first ) {
 543                         $dbw->query( $sql, 'Title::touchArray' );
 544                 }
 545                 */
 546                 // hack hack hack -- brion 2005-07-11. this was unfriendly to db.
 547                 // do them in small chunks:
 548                 $fname = 'Title::touchArray';
 549                 foreach( $titles as $title ) {
 550                         $dbw->update( 'page',
 551                                 array( 'page_touched' => $timestamp ),
 552                                 array(
 553                                         'page_namespace' => $title->getNamespace(),
 554                                         'page_title'     => $title->getDBkey() ),
 555                                 $fname );
 556                 }
 557         }
 558
 559 #----------------------------------------------------------------------------
 560 #       Other stuff
 561 #----------------------------------------------------------------------------
 562
 563         /** Simple accessors */
 564         /**
 565          * Get the text form (spaces not underscores) of the main part
 566          * @return string
 567          * @access public
 568          */
 569         function getText() { return $this->mTextform; }
 570         /**
 571          * Get the URL-encoded form of the main part
 572          * @return string
 573          * @access public
 574          */
 575         function getPartialURL() { return $this->mUrlform; }
 576         /**
 577          * Get the main part with underscores
 578          * @return string
 579          * @access public
 580          */
 581         function getDBkey() { return $this->mDbkeyform; }
 582         /**
 583          * Get the namespace index, i.e. one of the NS_xxxx constants
 584          * @return int
 585          * @access public
 586          */
 587         function getNamespace() { return $this->mNamespace; }
 588         /**
 589          * Get the namespace text
 590          * @return string
 591          * @access public
 592          */
 593         function getNsText() {
 594                 global $wgContLang;
 595                 return $wgContLang->getNsText( $this->mNamespace );
 596         }
 597         /**
 598          * Get the namespace text of the subject (rather than talk) page
 599          * @return string
 600          * @access public
 601          */
 602         function getSubjectNsText() {
 603                 global $wgContLang;
 604                 return $wgContLang->getNsText( Namespace::getSubject( $this->mNamespace ) );
 605         }
 606
 607         /**
 608          * Get the interwiki prefix (or null string)
 609          * @return string
 610          * @access public
 611          */
 612         function getInterwiki() { return $this->mInterwiki; }
 613         /**
 614          * Get the Title fragment (i.e. the bit after the #)
 615          * @return string
 616          * @access public
 617          */
 618         function getFragment() { return $this->mFragment; }
 619         /**
 620          * Get the default namespace index, for when there is no namespace
 621          * @return int
 622          * @access public
 623          */
 624         function getDefaultNamespace() { return $this->mDefaultNamespace; }
 625
 626         /**
 627          * Get title for search index
 628          * @return string a stripped-down title string ready for the
 629          *      search index
 630          */
 631         function getIndexTitle() {
 632                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 633         }
 634
 635         /**
 636          * Get the prefixed database key form
 637          * @return string the prefixed title, with underscores and
 638          *      any interwiki and namespace prefixes
 639          * @access public
 640          */
 641         function getPrefixedDBkey() {
 642                 $s = $this->prefix( $this->mDbkeyform );
 643                 $s = str_replace( ' ', '_', $s );
 644                 return $s;
 645         }
 646
 647         /**
 648          * Get the prefixed title with spaces.
 649          * This is the form usually used for display
 650          * @return string the prefixed title, with spaces
 651          * @access public
 652          */
 653         function getPrefixedText() {
 654                 global $wgContLang;
 655                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 656                         $s = $this->prefix( $this->mTextform );
 657                         $s = str_replace( '_', ' ', $s );
 658                         $this->mPrefixedText = $s;
 659                 }
 660                 return $this->mPrefixedText;
 661         }
 662
 663         /**
 664          * Get the prefixed title with spaces, plus any fragment
 665          * (part beginning with '#')
 666          * @return string the prefixed title, with spaces and
 667          *      the fragment, including '#'
 668          * @access public
 669          */
 670         function getFullText() {
 671                 global $wgContLang;
 672                 $text = $this->getPrefixedText();
 673                 if( '' != $this->mFragment ) {
 674                         $text .= '#' . $this->mFragment;
 675                 }
 676                 return $text;
 677         }
 678
 679         /**
 680          * Get a URL-encoded title (not an actual URL) including interwiki
 681          * @return string the URL-encoded form
 682          * @access public
 683          */
 684         function getPrefixedURL() {
 685                 $s = $this->prefix( $this->mDbkeyform );
 686                 $s = str_replace( ' ', '_', $s );
 687
 688                 $s = wfUrlencode ( $s ) ;
 689
 690                 # Cleaning up URL to make it look nice -- is this safe?
 691                 $s = str_replace( '%28', '(', $s );
 692                 $s = str_replace( '%29', ')', $s );
 693
 694                 return $s;
 695         }
 696
 697         /**
 698          * Get a real URL referring to this title, with interwiki link and
 699          * fragment
 700          *
 701          * @param string $query an optional query string, not used
 702          *      for interwiki links
 703          * @return string the URL
 704          * @access public
 705          */
 706         function getFullURL( $query = '' ) {
 707                 global $wgContLang, $wgServer, $wgRequest;
 708
 709                 if ( '' == $this->mInterwiki ) {
 710                         $url = $this->getLocalUrl( $query );
 711
 712                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 713                         // Correct fix would be to move the prepending elsewhere.
 714                         if ($wgRequest->getVal('action') != 'render') {
 715                                 $url = $wgServer . $url;
 716                         }
 717                 } else {
 718                         $baseUrl = $this->getInterwikiLink( $this->mInterwiki );
 719
 720                         $namespace = $wgContLang->getNsText( $this->mNamespace );
 721                         if ( '' != $namespace ) {
 722                                 # Can this actually happen? Interwikis shouldn't be parsed.
 723                                 $namespace .= ':';
 724                         }
 725                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 726                         if( $query != '' ) {
 727                                 if( false === strpos( $url, '?' ) ) {
 728                                         $url .= '?';
 729                                 } else {
 730                                         $url .= '&';
 731                                 }
 732                                 $url .= $query;
 733                         }
 734                         if ( '' != $this->mFragment ) {
 735                                 $url .= '#' . $this->mFragment;
 736                         }
 737                 }
 738                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 739                 return $url;
 740         }
 741
 742         /**
 743          * Get a URL with no fragment or server name.  If this page is generated
 744          * with action=render, $wgServer is prepended.
 745          * @param string $query an optional query string; if not specified,
 746          *      $wgArticlePath will be used.
 747          * @return string the URL
 748          * @access public
 749          */
 750         function getLocalURL( $query = '' ) {
 751                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 752
 753                 if ( $this->isExternal() ) {
 754                         $url = $this->getFullURL();
 755                         if ( $query ) {
 756                                 // This is currently only used for edit section links in the
 757                                 // context of interwiki transclusion. In theory we should
 758                                 // append the query to the end of any existing query string,
 759                                 // but interwiki transclusion is already broken in that case.
 760                                 $url .= "?$query";
 761                         }
 762                 } else {
 763                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 764                         if ( $query == '' ) {
 765                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
 766                         } else {
 767                                 global $wgActionPaths;
 768                                 $url = false;
 769                                 if( !empty( $wgActionPaths ) &&
 770                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 771                                 {
 772                                         $action = urldecode( $matches[2] );
 773                                         if( isset( $wgActionPaths[$action] ) ) {
 774                                                 $query = $matches[1];
 775                                                 if( isset( $matches[4] ) ) $query .= $matches[4];
 776                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 777                                                 if( $query != '' ) $url .= '?' . $query;
 778                                         }
 779                                 }
 780                                 if ( $url === false ) {
 781                                         if ( $query == '-' ) {
 782                                                 $query = '';
 783                                         }
 784                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 785                                 }
 786                         }
 787
 788                         // FIXME: this causes breakage in various places when we
 789                         // actually expected a local URL and end up with dupe prefixes.
 790                         if ($wgRequest->getVal('action') == 'render') {
 791                                 $url = $wgServer . $url;
 792                         }
 793                 }
 794                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 795                 return $url;
 796         }
 797
 798         /**
 799          * Get an HTML-escaped version of the URL form, suitable for
 800          * using in a link, without a server name or fragment
 801          * @param string $query an optional query string
 802          * @return string the URL
 803          * @access public
 804          */
 805         function escapeLocalURL( $query = '' ) {
 806                 return htmlspecialchars( $this->getLocalURL( $query ) );
 807         }
 808
 809         /**
 810          * Get an HTML-escaped version of the URL form, suitable for
 811          * using in a link, including the server name and fragment
 812          *
 813          * @return string the URL
 814          * @param string $query an optional query string
 815          * @access public
 816          */
 817         function escapeFullURL( $query = '' ) {
 818                 return htmlspecialchars( $this->getFullURL( $query ) );
 819         }
 820
 821         /**
 822          * Get the URL form for an internal link.
 823          * - Used in various Squid-related code, in case we have a different
 824          * internal hostname for the server from the exposed one.
 825          *
 826          * @param string $query an optional query string
 827          * @return string the URL
 828          * @access public
 829          */
 830         function getInternalURL( $query = '' ) {
 831                 global $wgInternalServer;
 832                 $url = $wgInternalServer . $this->getLocalURL( $query );
 833                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 834                 return $url;
 835         }
 836
 837         /**
 838          * Get the edit URL for this Title
 839          * @return string the URL, or a null string if this is an
 840          *      interwiki link
 841          * @access public
 842          */
 843         function getEditURL() {
 844                 global $wgServer, $wgScript;
 845
 846                 if ( '' != $this->mInterwiki ) { return ''; }
 847                 $s = $this->getLocalURL( 'action=edit' );
 848
 849                 return $s;
 850         }
 851
 852         /**
 853          * Get the HTML-escaped displayable text form.
 854          * Used for the title field in <a> tags.
 855          * @return string the text, including any prefixes
 856          * @access public
 857          */
 858         function getEscapedText() {
 859                 return htmlspecialchars( $this->getPrefixedText() );
 860         }
 861
 862         /**
 863          * Is this Title interwiki?
 864          * @return boolean
 865          * @access public
 866          */
 867         function isExternal() { return ( '' != $this->mInterwiki ); }
 868
 869         /**
 870          * Does the title correspond to a protected article?
 871          * @param string $what the action the page is protected from,
 872          *      by default checks move and edit
 873          * @return boolean
 874          * @access public
 875          */
 876         function isProtected( $action = '' ) {
 877                 global $wgRestrictionLevels;
 878                 if ( -1 == $this->mNamespace ) { return true; }
 879
 880                 if( $action == 'edit' || $action == '' ) {
 881                         $r = $this->getRestrictions( 'edit' );
 882                         foreach( $wgRestrictionLevels as $level ) {
 883                                 if( in_array( $level, $r ) && $level != '' ) {
 884                                         return( true );
 885                                 }
 886                         }
 887                 }
 888
 889                 if( $action == 'move' || $action == '' ) {
 890                         $r = $this->getRestrictions( 'move' );
 891                         foreach( $wgRestrictionLevels as $level ) {
 892                                 if( in_array( $level, $r ) && $level != '' ) {
 893                                         return( true );
 894                                 }
 895                         }
 896                 }
 897
 898                 return false;
 899         }
 900
 901         /**
 902          * Is $wgUser is watching this page?
 903          * @return boolean
 904          * @access public
 905          */
 906         function userIsWatching() {
 907                 global $wgUser;
 908
 909                 if ( is_null( $this->mWatched ) ) {
 910                         if ( -1 == $this->mNamespace || 0 == $wgUser->getID()) {
 911                                 $this->mWatched = false;
 912                         } else {
 913                                 $this->mWatched = $wgUser->isWatched( $this );
 914                         }
 915                 }
 916                 return $this->mWatched;
 917         }
 918
 919         /**
 920          * Can $wgUser perform $action this page?
 921          * @param string $action action that permission needs to be checked for
 922          * @return boolean
 923          * @access private
 924          */
 925         function userCan($action) {
 926                 $fname = 'Title::userCan';
 927                 wfProfileIn( $fname );
 928
 929                 global $wgUser;
 930                 if( NS_SPECIAL == $this->mNamespace ) {
 931                         wfProfileOut( $fname );
 932                         return false;
 933                 }
 934                 // XXX: This is the code that prevents unprotecting a page in NS_MEDIAWIKI
 935                 // from taking effect -ævar
 936                 if( NS_MEDIAWIKI == $this->mNamespace &&
 937                     !$wgUser->isAllowed('editinterface') ) {
 938                         wfProfileOut( $fname );
 939                         return false;
 940                 }
 941
 942                 if( $this->mDbkeyform == '_' ) {
 943                         # FIXME: Is this necessary? Shouldn't be allowed anyway...
 944                         wfProfileOut( $fname );
 945                         return false;
 946                 }
 947
 948                 # protect global styles and js
 949                 if ( NS_MEDIAWIKI == $this->mNamespace
 950                  && preg_match("/\\.(css|js)$/", $this->mTextform )
 951                      && !$wgUser->isAllowed('editinterface') ) {
 952                         wfProfileOut( $fname );
 953                         return false;
 954                 }
 955
 956                 # protect css/js subpages of user pages
 957                 # XXX: this might be better using restrictions
 958                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssJsSubpage() from working
 959                 if( NS_USER == $this->mNamespace
 960                         && preg_match("/\\.(css|js)$/", $this->mTextform )
 961                         && !$wgUser->isAllowed('editinterface')
 962                         && !preg_match('/^'.preg_quote($wgUser->getName(), '/').'\//', $this->mTextform) ) {
 963                         wfProfileOut( $fname );
 964                         return false;
 965                 }
 966
 967                 foreach( $this->getRestrictions($action) as $right ) {
 968                         // Backwards compatibility, rewrite sysop -> protect
 969                         if ( $right == 'sysop' ) {
 970                                 $right = 'protect';
 971                         }
 972                         if( '' != $right && !$wgUser->isAllowed( $right ) ) {
 973                                 wfProfileOut( $fname );
 974                                 return false;
 975                         }
 976                 }
 977
 978                 if( $action == 'move' &&
 979                         !( $this->isMovable() && $wgUser->isAllowed( 'move' ) ) ) {
 980                         wfProfileOut( $fname );
 981                         return false;
 982                 }
 983
 984                 if( $action == 'create' ) {
 985                         if( (  $this->isTalkPage() && !$wgUser->isAllowed( 'createtalk' ) ) ||
 986                                 ( !$this->isTalkPage() && !$wgUser->isAllowed( 'createpage' ) ) ) {
 987                                 return false;
 988                         }
 989                 }
 990
 991                 wfProfileOut( $fname );
 992                 return true;
 993         }
 994
 995         /**
 996          * Can $wgUser edit this page?
 997          * @return boolean
 998          * @access public
 999          */
1000         function userCanEdit() {
1001                 return $this->userCan('edit');
1002         }
1003
1004         /**
1005          * Can $wgUser move this page?
1006          * @return boolean
1007          * @access public
1008          */
1009         function userCanMove() {
1010                 return $this->userCan('move');
1011         }
1012
1013         /**
1014          * Would anybody with sufficient privileges be able to move this page?
1015          * Some pages just aren't movable.
1016          *
1017          * @return boolean
1018          * @access public
1019          */
1020         function isMovable() {
1021                 return Namespace::isMovable( $this->getNamespace() )
1022                         && $this->getInterwiki() == '';
1023         }
1024
1025         /**
1026          * Can $wgUser read this page?
1027          * @return boolean
1028          * @access public
1029          */
1030         function userCanRead() {
1031                 global $wgUser;
1032
1033                 if( $wgUser->isAllowed('read') ) {
1034                         return true;
1035                 } else {
1036                         global $wgWhitelistRead;
1037
1038                         /** If anon users can create an account,
1039                             they need to reach the login page first! */
1040                         if( $wgUser->isAllowed( 'createaccount' )
1041                             && $this->getNamespace() == NS_SPECIAL
1042                             && $this->getText() == 'Userlogin' ) {
1043                                 return true;
1044                         }
1045
1046                         /** some pages are explicitly allowed */
1047                         $name = $this->getPrefixedText();
1048                         if( $wgWhitelistRead && in_array( $name, $wgWhitelistRead ) ) {
1049                                 return true;
1050                         }
1051
1052                         # Compatibility with old settings
1053                         if( $wgWhitelistRead && $this->getNamespace() == NS_MAIN ) {
1054                                 if( in_array( ':' . $name, $wgWhitelistRead ) ) {
1055                                         return true;
1056                                 }
1057                         }
1058                 }
1059                 return false;
1060         }
1061
1062         /**
1063          * Is this a talk page of some sort?
1064          * @return bool
1065          * @access public
1066          */
1067         function isTalkPage() {
1068                 return Namespace::isTalk( $this->getNamespace() );
1069         }
1070
1071         /**
1072          * Is this a .css or .js subpage of a user page?
1073          * @return bool
1074          * @access public
1075          */
1076         function isCssJsSubpage() {
1077                 return ( NS_USER == $this->mNamespace and preg_match("/\\.(css|js)$/", $this->mTextform ) );
1078         }
1079         /**
1080          * Is this a .css subpage of a user page?
1081          * @return bool
1082          * @access public
1083          */
1084         function isCssSubpage() {
1085                 return ( NS_USER == $this->mNamespace and preg_match("/\\.css$/", $this->mTextform ) );
1086         }
1087         /**
1088          * Is this a .js subpage of a user page?
1089          * @return bool
1090          * @access public
1091          */
1092         function isJsSubpage() {
1093                 return ( NS_USER == $this->mNamespace and preg_match("/\\.js$/", $this->mTextform ) );
1094         }
1095         /**
1096          * Protect css/js subpages of user pages: can $wgUser edit
1097          * this page?
1098          *
1099          * @return boolean
1100          * @todo XXX: this might be better using restrictions
1101          * @access public
1102          */
1103         function userCanEditCssJsSubpage() {
1104                 global $wgUser;
1105                 return ( $wgUser->isAllowed('editinterface') or preg_match('/^'.preg_quote($wgUser->getName(), '/').'\//', $this->mTextform) );
1106         }
1107
1108         /**
1109          * Loads a string into mRestrictions array
1110          * @param string $res restrictions in string format
1111          * @access public
1112          */
1113         function loadRestrictions( $res ) {
1114                 foreach( explode( ':', trim( $res ) ) as $restrict ) {
1115                         $temp = explode( '=', trim( $restrict ) );
1116                         if(count($temp) == 1) {
1117                                 // old format should be treated as edit/move restriction
1118                                 $this->mRestrictions["edit"] = explode( ',', trim( $temp[0] ) );
1119                                 $this->mRestrictions["move"] = explode( ',', trim( $temp[0] ) );
1120                         } else {
1121                                 $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
1122                         }
1123                 }
1124                 $this->mRestrictionsLoaded = true;
1125         }
1126
1127         /**
1128          * Accessor/initialisation for mRestrictions
1129          * @param string $action action that permission needs to be checked for
1130          * @return array the array of groups allowed to edit this article
1131          * @access public
1132          */
1133         function getRestrictions($action) {
1134                 $id = $this->getArticleID();
1135                 if ( 0 == $id ) { return array(); }
1136
1137                 if ( ! $this->mRestrictionsLoaded ) {
1138                         $dbr =& wfGetDB( DB_SLAVE );
1139                         $res = $dbr->selectField( 'page', 'page_restrictions', 'page_id='.$id );
1140                         $this->loadRestrictions( $res );
1141                 }
1142                 if( isset( $this->mRestrictions[$action] ) ) {
1143                         return $this->mRestrictions[$action];
1144                 }
1145                 return array();
1146         }
1147
1148         /**
1149          * Is there a version of this page in the deletion archive?
1150          * @return int the number of archived revisions
1151          * @access public
1152          */
1153         function isDeleted() {
1154                 $fname = 'Title::isDeleted';
1155                 if ( $this->getNamespace() < 0 ) {
1156                         $n = 0;
1157                 } else {
1158                         $dbr =& wfGetDB( DB_SLAVE );
1159                         $n = $dbr->selectField( 'archive', 'COUNT(*)', array( 'ar_namespace' => $this->getNamespace(),
1160                                 'ar_title' => $this->getDBkey() ), $fname );
1161                 }
1162                 return (int)$n;
1163         }
1164
1165         /**
1166          * Get the article ID for this Title from the link cache,
1167          * adding it if necessary
1168          * @param int $flags a bit field; may be GAID_FOR_UPDATE to select
1169          *      for update
1170          * @return int the ID
1171          * @access public
1172          */
1173         function getArticleID( $flags = 0 ) {
1174                 $linkCache =& LinkCache::singleton();
1175                 if ( $flags & GAID_FOR_UPDATE ) {
1176                         $oldUpdate = $linkCache->forUpdate( true );
1177                         $this->mArticleID = $linkCache->addLinkObj( $this );
1178                         $linkCache->forUpdate( $oldUpdate );
1179                 } else {
1180                         if ( -1 == $this->mArticleID ) {
1181                                 $this->mArticleID = $linkCache->addLinkObj( $this );
1182                         }
1183                 }
1184                 return $this->mArticleID;
1185         }
1186
1187         function getLatestRevID() {
1188                 if ($this->mLatestID !== false)
1189                         return $this->mLatestID;
1190
1191                 $db =& wfGetDB(DB_SLAVE);
1192                 return $this->mLatestID = $db->selectField( 'revision',
1193                         "max(rev_id)",
1194                         array('rev_page' => $this->getArticleID()),
1195                         'Title::getLatestRevID' );
1196         }
1197
1198         /**
1199          * This clears some fields in this object, and clears any associated
1200          * keys in the "bad links" section of the link cache.
1201          *
1202          * - This is called from Article::insertNewArticle() to allow
1203          * loading of the new page_id. It's also called from
1204          * Article::doDeleteArticle()
1205          *
1206          * @param int $newid the new Article ID
1207          * @access public
1208          */
1209         function resetArticleID( $newid ) {
1210                 $linkCache =& LinkCache::singleton();
1211                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
1212
1213                 if ( 0 == $newid ) { $this->mArticleID = -1; }
1214                 else { $this->mArticleID = $newid; }
1215                 $this->mRestrictionsLoaded = false;
1216                 $this->mRestrictions = array();
1217         }
1218
1219         /**
1220          * Updates page_touched for this page; called from LinksUpdate.php
1221          * @return bool true if the update succeded
1222          * @access public
1223          */
1224         function invalidateCache() {
1225                 global $wgUseFileCache;
1226
1227                 if ( wfReadOnly() ) {
1228                         return;
1229                 }
1230
1231                 $dbw =& wfGetDB( DB_MASTER );
1232                 $success = $dbw->update( 'page',
1233                         array( /* SET */
1234                                 'page_touched' => $dbw->timestamp()
1235                         ), array( /* WHERE */
1236                                 'page_namespace' => $this->getNamespace() ,
1237                                 'page_title' => $this->getDBkey()
1238                         ), 'Title::invalidateCache'
1239                 );
1240
1241                 if ($wgUseFileCache) {
1242                         $cache = new CacheManager($this);
1243                         @unlink($cache->fileCacheName());
1244                 }
1245
1246                 return $success;
1247         }
1248
1249         /**
1250          * Prefix some arbitrary text with the namespace or interwiki prefix
1251          * of this object
1252          *
1253          * @param string $name the text
1254          * @return string the prefixed text
1255          * @access private
1256          */
1257         /* private */ function prefix( $name ) {
1258                 global $wgContLang;
1259
1260                 $p = '';
1261                 if ( '' != $this->mInterwiki ) {
1262                         $p = $this->mInterwiki . ':';
1263                 }
1264                 if ( 0 != $this->mNamespace ) {
1265                         $p .= $wgContLang->getNsText( $this->mNamespace ) . ':';
1266                 }
1267                 return $p . $name;
1268         }
1269
1270         /**
1271          * Secure and split - main initialisation function for this object
1272          *
1273          * Assumes that mDbkeyform has been set, and is urldecoded
1274          * and uses underscores, but not otherwise munged.  This function
1275          * removes illegal characters, splits off the interwiki and
1276          * namespace prefixes, sets the other forms, and canonicalizes
1277          * everything.
1278          * @return bool true on success
1279          * @access private
1280          */
1281         /* private */ function secureAndSplit() {
1282                 global $wgContLang, $wgLocalInterwiki, $wgCapitalLinks;
1283                 $fname = 'Title::secureAndSplit';
1284
1285                 # Initialisation
1286                 static $rxTc = false;
1287                 if( !$rxTc ) {
1288                         # % is needed as well
1289                         $rxTc = '/[^' . Title::legalChars() . ']|%[0-9A-Fa-f]{2}/S';
1290                 }
1291
1292                 $this->mInterwiki = $this->mFragment = '';
1293                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
1294
1295                 # Clean up whitespace
1296                 #
1297                 $t = preg_replace( '/[ _]+/', '_', $this->mDbkeyform );
1298                 $t = trim( $t, '_' );
1299
1300                 if ( '' == $t ) {
1301                         return false;
1302                 }
1303
1304                 if( false !== strpos( $t, UTF8_REPLACEMENT ) ) {
1305                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
1306                         return false;
1307                 }
1308
1309                 $this->mDbkeyform = $t;
1310
1311                 # Initial colon indicates main namespace rather than specified default
1312                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
1313                 if ( ':' == $t{0} ) {
1314                         $this->mNamespace = NS_MAIN;
1315                         $t = substr( $t, 1 ); # remove the colon but continue processing
1316                 }
1317
1318                 # Namespace or interwiki prefix
1319                 $firstPass = true;
1320                 do {
1321                         if ( preg_match( "/^(.+?)_*:_*(.*)$/S", $t, $m ) ) {
1322                                 $p = $m[1];
1323                                 $lowerNs = strtolower( $p );
1324                                 if ( $ns = Namespace::getCanonicalIndex( $lowerNs ) ) {
1325                                         # Canonical namespace
1326                                         $t = $m[2];
1327                                         $this->mNamespace = $ns;
1328                                 } elseif ( $ns = $wgContLang->getNsIndex( $lowerNs )) {
1329                                         # Ordinary namespace
1330                                         $t = $m[2];
1331                                         $this->mNamespace = $ns;
1332                                 } elseif( $this->getInterwikiLink( $p ) ) {
1333                                         if( !$firstPass ) {
1334                                                 # Can't make a local interwiki link to an interwiki link.
1335                                                 # That's just crazy!
1336                                                 return false;
1337                                         }
1338
1339                                         # Interwiki link
1340                                         $t = $m[2];
1341                                         $this->mInterwiki = strtolower( $p );
1342
1343                                         # Redundant interwiki prefix to the local wiki
1344                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
1345                                                 if( $t == '' ) {
1346                                                         # Can't have an empty self-link
1347                                                         return false;
1348                                                 }
1349                                                 $this->mInterwiki = '';
1350                                                 $firstPass = false;
1351                                                 # Do another namespace split...
1352                                                 continue;
1353                                         }
1354
1355                                         # If there's an initial colon after the interwiki, that also
1356                                         # resets the default namespace
1357                                         if ( $t !== '' && $t[0] == ':' ) {
1358                                                 $this->mNamespace = NS_MAIN;
1359                                                 $t = substr( $t, 1 );
1360                                         }
1361                                 }
1362                                 # If there's no recognized interwiki or namespace,
1363                                 # then let the colon expression be part of the title.
1364                         }
1365                         break;
1366                 } while( true );
1367                 $r = $t;
1368
1369                 # We already know that some pages won't be in the database!
1370                 #
1371                 if ( '' != $this->mInterwiki || -1 == $this->mNamespace ) {
1372                         $this->mArticleID = 0;
1373                 }
1374                 $f = strstr( $r, '#' );
1375                 if ( false !== $f ) {
1376                         $this->mFragment = substr( $f, 1 );
1377                         $r = substr( $r, 0, strlen( $r ) - strlen( $f ) );
1378                         # remove whitespace again: prevents "Foo_bar_#"
1379                         # becoming "Foo_bar_"
1380                         $r = preg_replace( '/_*$/', '', $r );
1381                 }
1382
1383                 # Reject illegal characters.
1384                 #
1385                 if( preg_match( $rxTc, $r ) ) {
1386                         return false;
1387                 }
1388
1389                 /**
1390                  * Pages with "/./" or "/../" appearing in the URLs will
1391                  * often be unreachable due to the way web browsers deal
1392                  * with 'relative' URLs. Forbid them explicitly.
1393                  */
1394                 if ( strpos( $r, '.' ) !== false &&
1395                      ( $r === '.' || $r === '..' ||
1396                        strpos( $r, './' ) === 0  ||
1397                        strpos( $r, '../' ) === 0 ||
1398                        strpos( $r, '/./' ) !== false ||
1399                        strpos( $r, '/../' ) !== false ) )
1400                 {
1401                         return false;
1402                 }
1403
1404                 # We shouldn't need to query the DB for the size.
1405                 #$maxSize = $dbr->textFieldSize( 'page', 'page_title' );
1406                 if ( strlen( $r ) > 255 ) {
1407                         return false;
1408                 }
1409
1410                 /**
1411                  * Normally, all wiki links are forced to have
1412                  * an initial capital letter so [[foo]] and [[Foo]]
1413                  * point to the same place.
1414                  *
1415                  * Don't force it for interwikis, since the other
1416                  * site might be case-sensitive.
1417                  */
1418                 if( $wgCapitalLinks && $this->mInterwiki == '') {
1419                         $t = $wgContLang->ucfirst( $r );
1420                 } else {
1421                         $t = $r;
1422                 }
1423
1424                 /**
1425                  * Can't make a link to a namespace alone...
1426                  * "empty" local links can only be self-links
1427                  * with a fragment identifier.
1428                  */
1429                 if( $t == '' &&
1430                         $this->mInterwiki == '' &&
1431                         $this->mNamespace != NS_MAIN ) {
1432                         return false;
1433                 }
1434
1435                 # Fill fields
1436                 $this->mDbkeyform = $t;
1437                 $this->mUrlform = wfUrlencode( $t );
1438
1439                 $this->mTextform = str_replace( '_', ' ', $t );
1440
1441                 return true;
1442         }
1443
1444         /**
1445          * Get a Title object associated with the talk page of this article
1446          * @return Title the object for the talk page
1447          * @access public
1448          */
1449         function getTalkPage() {
1450                 return Title::makeTitle( Namespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1451         }
1452
1453         /**
1454          * Get a title object associated with the subject page of this
1455          * talk page
1456          *
1457          * @return Title the object for the subject page
1458          * @access public
1459          */
1460         function getSubjectPage() {
1461                 return Title::makeTitle( Namespace::getSubject( $this->getNamespace() ), $this->getDBkey() );
1462         }
1463
1464         /**
1465          * Get an array of Title objects linking to this Title
1466          * Also stores the IDs in the link cache.
1467          *
1468          * @param string $options may be FOR UPDATE
1469          * @return array the Title objects linking here
1470          * @access public
1471          */
1472         function getLinksTo( $options = '', $table = 'pagelinks', $prefix = 'pl' ) {
1473                 $linkCache =& LinkCache::singleton();
1474                 $id = $this->getArticleID();
1475
1476                 if ( $options ) {
1477                         $db =& wfGetDB( DB_MASTER );
1478                 } else {
1479                         $db =& wfGetDB( DB_SLAVE );
1480                 }
1481
1482                 $res = $db->select( array( 'page', $table ),
1483                         array( 'page_namespace', 'page_title', 'page_id' ),
1484                         array(
1485                                 "{$prefix}_from=page_id",
1486                                 "{$prefix}_namespace" => $this->getNamespace(),
1487                                 "{$prefix}_title"     => $this->getDbKey() ),
1488                         'Title::getLinksTo',
1489                         $options );
1490
1491                 $retVal = array();
1492                 if ( $db->numRows( $res ) ) {
1493                         while ( $row = $db->fetchObject( $res ) ) {
1494                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
1495                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj );
1496                                         $retVal[] = $titleObj;
1497                                 }
1498                         }
1499                 }
1500                 $db->freeResult( $res );
1501                 return $retVal;
1502         }
1503
1504         /**
1505          * Get an array of Title objects using this Title as a template
1506          * Also stores the IDs in the link cache.
1507          *
1508          * @param string $options may be FOR UPDATE
1509          * @return array the Title objects linking here
1510          * @access public
1511          */
1512         function getTemplateLinksTo( $options = '' ) {
1513                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
1514         }
1515
1516         /**
1517          * Get an array of Title objects referring to non-existent articles linked from this page
1518          *
1519          * @param string $options may be FOR UPDATE
1520          * @return array the Title objects
1521          * @access public
1522          */
1523         function getBrokenLinksFrom( $options = '' ) {
1524                 if ( $options ) {
1525                         $db =& wfGetDB( DB_MASTER );
1526                 } else {
1527                         $db =& wfGetDB( DB_SLAVE );
1528                 }
1529
1530                 $res = $db->safeQuery(
1531                           "SELECT pl_namespace, pl_title
1532                              FROM !
1533                         LEFT JOIN !
1534                                ON pl_namespace=page_namespace
1535                               AND pl_title=page_title
1536                             WHERE pl_from=?
1537                               AND page_namespace IS NULL
1538                                   !",
1539                         $db->tableName( 'pagelinks' ),
1540                         $db->tableName( 'page' ),
1541                         $this->getArticleId(),
1542                         $options );
1543
1544                 $retVal = array();
1545                 if ( $db->numRows( $res ) ) {
1546                         while ( $row = $db->fetchObject( $res ) ) {
1547                                 $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
1548                         }
1549                 }
1550                 $db->freeResult( $res );
1551                 return $retVal;
1552         }
1553
1554
1555         /**
1556          * Get a list of URLs to purge from the Squid cache when this
1557          * page changes
1558          *
1559          * @return array the URLs
1560          * @access public
1561          */
1562         function getSquidURLs() {
1563                 return array(
1564                         $this->getInternalURL(),
1565                         $this->getInternalURL( 'action=history' )
1566                 );
1567         }
1568
1569         /**
1570          * Move this page without authentication
1571          * @param Title &$nt the new page Title
1572          * @access public
1573          */
1574         function moveNoAuth( &$nt ) {
1575                 return $this->moveTo( $nt, false );
1576         }
1577
1578         /**
1579          * Check whether a given move operation would be valid.
1580          * Returns true if ok, or a message key string for an error message
1581          * if invalid. (Scarrrrry ugly interface this.)
1582          * @param Title &$nt the new title
1583          * @param bool $auth indicates whether $wgUser's permissions
1584          *      should be checked
1585          * @return mixed true on success, message name on failure
1586          * @access public
1587          */
1588         function isValidMoveOperation( &$nt, $auth = true ) {
1589                 global $wgUser;
1590                 if( !$this or !$nt ) {
1591                         return 'badtitletext';
1592                 }
1593                 if( $this->equals( $nt ) ) {
1594                         return 'selfmove';
1595                 }
1596                 if( !$this->isMovable() || !$nt->isMovable() ) {
1597                         return 'immobile_namespace';
1598                 }
1599
1600                 $oldid = $this->getArticleID();
1601                 $newid = $nt->getArticleID();
1602
1603                 if ( strlen( $nt->getDBkey() ) < 1 ) {
1604                         return 'articleexists';
1605                 }
1606                 if ( ( '' == $this->getDBkey() ) ||
1607                          ( !$oldid ) ||
1608                      ( '' == $nt->getDBkey() ) ) {
1609                         return 'badarticleerror';
1610                 }
1611
1612                 if ( $auth && (
1613                                 !$this->userCanEdit() || !$nt->userCanEdit() ||
1614                                 !$this->userCanMove() || !$nt->userCanMove() ) ) {
1615                         return 'protectedpage';
1616                 }
1617
1618                 # The move is allowed only if (1) the target doesn't exist, or
1619                 # (2) the target is a redirect to the source, and has no history
1620                 # (so we can undo bad moves right after they're done).
1621
1622                 if ( 0 != $newid ) { # Target exists; check for validity
1623                         if ( ! $this->isValidMoveTarget( $nt ) ) {
1624                                 return 'articleexists';
1625                         }
1626                 }
1627                 return true;
1628         }
1629
1630         /**
1631          * Move a title to a new location
1632          * @param Title &$nt the new title
1633          * @param bool $auth indicates whether $wgUser's permissions
1634          *      should be checked
1635          * @return mixed true on success, message name on failure
1636          * @access public
1637          */
1638         function moveTo( &$nt, $auth = true, $reason = '' ) {
1639                 $err = $this->isValidMoveOperation( $nt, $auth );
1640                 if( is_string( $err ) ) {
1641                         return $err;
1642                 }
1643
1644                 $pageid = $this->getArticleID();
1645                 if( $nt->exists() ) {
1646                         $this->moveOverExistingRedirect( $nt, $reason );
1647                         $pageCountChange = 0;
1648                 } else { # Target didn't exist, do normal move.
1649                         $this->moveToNewTitle( $nt, $reason );
1650                         $pageCountChange = 1;
1651                 }
1652                 $redirid = $this->getArticleID();
1653
1654                 # Fixing category links (those without piped 'alternate' names) to be sorted under the new title
1655                 $dbw =& wfGetDB( DB_MASTER );
1656                 $categorylinks = $dbw->tableName( 'categorylinks' );
1657                 $sql = "UPDATE $categorylinks SET cl_sortkey=" . $dbw->addQuotes( $nt->getPrefixedText() ) .
1658                         " WHERE cl_from=" . $dbw->addQuotes( $pageid ) .
1659                         " AND cl_sortkey=" . $dbw->addQuotes( $this->getPrefixedText() );
1660                 $dbw->query( $sql, 'SpecialMovepage::doSubmit' );
1661
1662                 # Update watchlists
1663
1664                 $oldnamespace = $this->getNamespace() & ~1;
1665                 $newnamespace = $nt->getNamespace() & ~1;
1666                 $oldtitle = $this->getDBkey();
1667                 $newtitle = $nt->getDBkey();
1668
1669                 if( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
1670                         WatchedItem::duplicateEntries( $this, $nt );
1671                 }
1672
1673                 # Update search engine
1674                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
1675                 $u->doUpdate();
1676                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
1677                 $u->doUpdate();
1678
1679                 # Update site_stats
1680                 if ( $this->getNamespace() == NS_MAIN and $nt->getNamespace() != NS_MAIN ) {
1681                         # Moved out of main namespace
1682                         # not viewed, edited, removing
1683                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange);
1684                 } elseif ( $this->getNamespace() != NS_MAIN and $nt->getNamespace() == NS_MAIN ) {
1685                         # Moved into main namespace
1686                         # not viewed, edited, adding
1687                         $u = new SiteStatsUpdate( 0, 1, +1, $pageCountChange );
1688                 } elseif ( $pageCountChange ) {
1689                         # Added redirect
1690                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
1691                 } else{
1692                         $u = false;
1693                 }
1694                 if ( $u ) {
1695                         $u->doUpdate();
1696                 }
1697
1698                 global $wgUser;
1699                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
1700                 return true;
1701         }
1702
1703         /**
1704          * Move page to a title which is at present a redirect to the
1705          * source page
1706          *
1707          * @param Title &$nt the page to move to, which should currently
1708          *      be a redirect
1709          * @access private
1710          */
1711         function moveOverExistingRedirect( &$nt, $reason = '' ) {
1712                 global $wgUser, $wgUseSquid, $wgMwRedir;
1713                 $fname = 'Title::moveOverExistingRedirect';
1714                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
1715
1716                 if ( $reason ) {
1717                         $comment .= ": $reason";
1718                 }
1719
1720                 $now = wfTimestampNow();
1721                 $rand = wfRandom();
1722                 $newid = $nt->getArticleID();
1723                 $oldid = $this->getArticleID();
1724                 $dbw =& wfGetDB( DB_MASTER );
1725                 $linkCache =& LinkCache::singleton();
1726
1727                 # Delete the old redirect. We don't save it to history since
1728                 # by definition if we've got here it's rather uninteresting.
1729                 # We have to remove it so that the next step doesn't trigger
1730                 # a conflict on the unique namespace+title index...
1731                 $dbw->delete( 'page', array( 'page_id' => $newid ), $fname );
1732
1733                 # Save a null revision in the page's history notifying of the move
1734                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
1735                 $nullRevId = $nullRevision->insertOn( $dbw );
1736
1737                 # Change the name of the target page:
1738                 $dbw->update( 'page',
1739                         /* SET */ array(
1740                                 'page_touched'   => $dbw->timestamp($now),
1741                                 'page_namespace' => $nt->getNamespace(),
1742                                 'page_title'     => $nt->getDBkey(),
1743                                 'page_latest'    => $nullRevId,
1744                         ),
1745                         /* WHERE */ array( 'page_id' => $oldid ),
1746                         $fname
1747                 );
1748                 $linkCache->clearLink( $nt->getPrefixedDBkey() );
1749
1750                 # Recreate the redirect, this time in the other direction.
1751                 $redirectText = $wgMwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
1752                 $redirectArticle = new Article( $this );
1753                 $newid = $redirectArticle->insertOn( $dbw );
1754                 $redirectRevision = new Revision( array(
1755                         'page'    => $newid,
1756                         'comment' => $comment,
1757                         'text'    => $redirectText ) );
1758                 $revid = $redirectRevision->insertOn( $dbw );
1759                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
1760                 $linkCache->clearLink( $this->getPrefixedDBkey() );
1761
1762                 # Log the move
1763                 $log = new LogPage( 'move' );
1764                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText() ) );
1765
1766                 # Now, we record the link from the redirect to the new title.
1767                 # It should have no other outgoing links...
1768                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), $fname );
1769                 $dbw->insert( 'pagelinks',
1770                         array(
1771                                 'pl_from'      => $newid,
1772                                 'pl_namespace' => $nt->getNamespace(),
1773                                 'pl_title'     => $nt->getDbKey() ),
1774                         $fname );
1775
1776                 # Purge squid
1777                 if ( $wgUseSquid ) {
1778                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
1779                         $u = new SquidUpdate( $urls );
1780                         $u->doUpdate();
1781                 }
1782         }
1783
1784         /**
1785          * Move page to non-existing title.
1786          * @param Title &$nt the new Title
1787          * @access private
1788          */
1789         function moveToNewTitle( &$nt, $reason = '' ) {
1790                 global $wgUser, $wgUseSquid;
1791                 global $wgMwRedir;
1792                 $fname = 'MovePageForm::moveToNewTitle';
1793                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
1794                 if ( $reason ) {
1795                         $comment .= ": $reason";
1796                 }
1797
1798                 $newid = $nt->getArticleID();
1799                 $oldid = $this->getArticleID();
1800                 $dbw =& wfGetDB( DB_MASTER );
1801                 $now = $dbw->timestamp();
1802                 $rand = wfRandom();
1803                 $linkCache =& LinkCache::singleton();
1804
1805                 # Save a null revision in the page's history notifying of the move
1806                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
1807                 $nullRevId = $nullRevision->insertOn( $dbw );
1808
1809                 # Rename cur entry
1810                 $dbw->update( 'page',
1811                         /* SET */ array(
1812                                 'page_touched'   => $now,
1813                                 'page_namespace' => $nt->getNamespace(),
1814                                 'page_title'     => $nt->getDBkey(),
1815                                 'page_latest'    => $nullRevId,
1816                         ),
1817                         /* WHERE */ array( 'page_id' => $oldid ),
1818                         $fname
1819                 );
1820
1821                 $linkCache->clearLink( $nt->getPrefixedDBkey() );
1822
1823                 # Insert redirect
1824                 $redirectText = $wgMwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
1825                 $redirectArticle = new Article( $this );
1826                 $newid = $redirectArticle->insertOn( $dbw );
1827                 $redirectRevision = new Revision( array(
1828                         'page'    => $newid,
1829                         'comment' => $comment,
1830                         'text'    => $redirectText ) );
1831                 $revid = $redirectRevision->insertOn( $dbw );
1832                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
1833                 $linkCache->clearLink( $this->getPrefixedDBkey() );
1834
1835                 # Log the move
1836                 $log = new LogPage( 'move' );
1837                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText()) );
1838
1839                 # Purge caches as per article creation
1840                 Article::onArticleCreate( $nt );
1841
1842                 # Record the just-created redirect's linking to the page
1843                 $dbw->insert( 'pagelinks',
1844                         array(
1845                                 'pl_from'      => $newid,
1846                                 'pl_namespace' => $nt->getNamespace(),
1847                                 'pl_title'     => $nt->getDBkey() ),
1848                         $fname );
1849
1850                 # Non-existent target may have had broken links to it; these must
1851                 # now be touched to update link coloring.
1852                 $nt->touchLinks();
1853
1854                 # Purge old title from squid
1855                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
1856                 $titles = $nt->getLinksTo();
1857                 if ( $wgUseSquid ) {
1858                         $urls = $this->getSquidURLs();
1859                         foreach ( $titles as $linkTitle ) {
1860                                 $urls[] = $linkTitle->getInternalURL();
1861                         }
1862                         $u = new SquidUpdate( $urls );
1863                         $u->doUpdate();
1864                 }
1865         }
1866
1867         /**
1868          * Checks if $this can be moved to a given Title
1869          * - Selects for update, so don't call it unless you mean business
1870          *
1871          * @param Title &$nt the new title to check
1872          * @access public
1873          */
1874         function isValidMoveTarget( $nt ) {
1875
1876                 $fname = 'Title::isValidMoveTarget';
1877                 $dbw =& wfGetDB( DB_MASTER );
1878
1879                 # Is it a redirect?
1880                 $id  = $nt->getArticleID();
1881                 $obj = $dbw->selectRow( array( 'page', 'revision', 'text'),
1882                         array( 'page_is_redirect','old_text','old_flags' ),
1883                         array( 'page_id' => $id, 'page_latest=rev_id', 'rev_text_id=old_id' ),
1884                         $fname, 'FOR UPDATE' );
1885
1886                 if ( !$obj || 0 == $obj->page_is_redirect ) {
1887                         # Not a redirect
1888                         return false;
1889                 }
1890                 $text = Revision::getRevisionText( $obj );
1891
1892                 # Does the redirect point to the source?
1893                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
1894                         $redirTitle = Title::newFromText( $m[1] );
1895                         if( !is_object( $redirTitle ) ||
1896                                 $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() ) {
1897                                 return false;
1898                         }
1899                 } else {
1900                         # Fail safe
1901                         return false;
1902                 }
1903
1904                 # Does the article have a history?
1905                 $row = $dbw->selectRow( array( 'page', 'revision'),
1906                         array( 'rev_id' ),
1907                         array( 'page_namespace' => $nt->getNamespace(),
1908                                 'page_title' => $nt->getDBkey(),
1909                                 'page_id=rev_page AND page_latest != rev_id'
1910                         ), $fname, 'FOR UPDATE'
1911                 );
1912
1913                 # Return true if there was no history
1914                 return $row === false;
1915         }
1916
1917         /**
1918          * Create a redirect; fails if the title already exists; does
1919          * not notify RC
1920          *
1921          * @param Title $dest the destination of the redirect
1922          * @param string $comment the comment string describing the move
1923          * @return bool true on success
1924          * @access public
1925          */
1926         function createRedirect( $dest, $comment ) {
1927                 global $wgUser;
1928                 if ( $this->getArticleID() ) {
1929                         return false;
1930                 }
1931
1932                 $fname = 'Title::createRedirect';
1933                 $dbw =& wfGetDB( DB_MASTER );
1934
1935                 $article = new Article( $this );
1936                 $newid = $article->insertOn( $dbw );
1937                 $revision = new Revision( array(
1938                         'page'      => $newid,
1939                         'comment'   => $comment,
1940                         'text'      => "#REDIRECT [[" . $dest->getPrefixedText() . "]]\n",
1941                         ) );
1942                 $revisionId = $revision->insertOn( $dbw );
1943                 $article->updateRevisionOn( $dbw, $revision, 0 );
1944
1945                 # Link table
1946                 $dbw->insert( 'pagelinks',
1947                         array(
1948                                 'pl_from'      => $newid,
1949                                 'pl_namespace' => $dest->getNamespace(),
1950                                 'pl_title'     => $dest->getDbKey()
1951                         ), $fname
1952                 );
1953
1954                 Article::onArticleCreate( $this );
1955                 return true;
1956         }
1957
1958         /**
1959          * Get categories to which this Title belongs and return an array of
1960          * categories' names.
1961          *
1962          * @return array an array of parents in the form:
1963          *      $parent => $currentarticle
1964          * @access public
1965          */
1966         function getParentCategories() {
1967                 global $wgContLang,$wgUser;
1968
1969                 $titlekey = $this->getArticleId();
1970                 $dbr =& wfGetDB( DB_SLAVE );
1971                 $categorylinks = $dbr->tableName( 'categorylinks' );
1972
1973                 # NEW SQL
1974                 $sql = "SELECT * FROM $categorylinks"
1975                      ." WHERE cl_from='$titlekey'"
1976                          ." AND cl_from <> '0'"
1977                          ." ORDER BY cl_sortkey";
1978
1979                 $res = $dbr->query ( $sql ) ;
1980
1981                 if($dbr->numRows($res) > 0) {
1982                         while ( $x = $dbr->fetchObject ( $res ) )
1983                                 //$data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$x->cl_to);
1984                                 $data[$wgContLang->getNSText ( NS_CATEGORY ).':'.$x->cl_to] = $this->getFullText();
1985                         $dbr->freeResult ( $res ) ;
1986                 } else {
1987                         $data = '';
1988                 }
1989                 return $data;
1990         }
1991
1992         /**
1993          * Get a tree of parent categories
1994          * @param array $children an array with the children in the keys, to check for circular refs
1995          * @return array
1996          * @access public
1997          */
1998         function getParentCategoryTree( $children = array() ) {
1999                 $parents = $this->getParentCategories();
2000
2001                 if($parents != '') {
2002                         foreach($parents as $parent => $current) {
2003                                 if ( array_key_exists( $parent, $children ) ) {
2004                                         # Circular reference
2005                                         $stack[$parent] = array();
2006                                 } else {
2007                                         $nt = Title::newFromText($parent);
2008                                         $stack[$parent] = $nt->getParentCategoryTree( $children + array($parent => 1) );
2009                                 }
2010                         }
2011                         return $stack;
2012                 } else {
2013                         return array();
2014                 }
2015         }
2016
2017
2018         /**
2019          * Get an associative array for selecting this title from
2020          * the "page" table
2021          *
2022          * @return array
2023          * @access public
2024          */
2025         function pageCond() {
2026                 return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
2027         }
2028
2029         /**
2030          * Get the revision ID of the previous revision
2031          *
2032          * @param integer $revision  Revision ID. Get the revision that was before this one.
2033          * @return interger $oldrevision|false
2034          */
2035         function getPreviousRevisionID( $revision ) {
2036                 $dbr =& wfGetDB( DB_SLAVE );
2037                 return $dbr->selectField( 'revision', 'rev_id',
2038                         'rev_page=' . intval( $this->getArticleId() ) .
2039                         ' AND rev_id<' . intval( $revision ) . ' ORDER BY rev_id DESC' );
2040         }
2041
2042         /**
2043          * Get the revision ID of the next revision
2044          *
2045          * @param integer $revision  Revision ID. Get the revision that was after this one.
2046          * @return interger $oldrevision|false
2047          */
2048         function getNextRevisionID( $revision ) {
2049                 $dbr =& wfGetDB( DB_SLAVE );
2050                 return $dbr->selectField( 'revision', 'rev_id',
2051                         'rev_page=' . intval( $this->getArticleId() ) .
2052                         ' AND rev_id>' . intval( $revision ) . ' ORDER BY rev_id' );
2053         }
2054
2055         /**
2056          * Compare with another title.
2057          *
2058          * @param Title $title
2059          * @return bool
2060          */
2061         function equals( $title ) {
2062                 return $this->getInterwiki() == $title->getInterwiki()
2063                         && $this->getNamespace() == $title->getNamespace()
2064                         && $this->getDbkey() == $title->getDbkey();
2065         }
2066
2067         /**
2068          * Check if page exists
2069          * @return bool
2070          */
2071         function exists() {
2072                 return $this->getArticleId() != 0;
2073         }
2074
2075         /**
2076          * Should a link should be displayed as a known link, just based on its title?
2077          *
2078          * Currently, a self-link with a fragment and special pages are in
2079          * this category. Special pages never exist in the database.
2080          */
2081         function isAlwaysKnown() {
2082                 return  $this->isExternal() || ( 0 == $this->mNamespace && "" == $this->mDbkeyform )
2083                   || NS_SPECIAL == $this->mNamespace;
2084         }
2085
2086         /**
2087          * Update page_touched timestamps on pages linking to this title.
2088          * In principal, this could be backgrounded and could also do squid
2089          * purging.
2090          */
2091         function touchLinks() {
2092                 $fname = 'Title::touchLinks';
2093
2094                 $dbw =& wfGetDB( DB_MASTER );
2095
2096                 $res = $dbw->select( 'pagelinks',
2097                         array( 'pl_from' ),
2098                         array(
2099                                 'pl_namespace' => $this->getNamespace(),
2100                                 'pl_title'     => $this->getDbKey() ),
2101                         $fname );
2102
2103                 $toucharr = array();
2104                 while( $row = $dbw->fetchObject( $res ) ) {
2105                         $toucharr[] = $row->pl_from;
2106                 }
2107                 $dbw->freeResult( $res );
2108
2109                 if( $this->getNamespace() == NS_CATEGORY ) {
2110                         // Categories show up in a separate set of links as well
2111                         $res = $dbw->select( 'categorylinks',
2112                                 array( 'cl_from' ),
2113                                 array( 'cl_to' => $this->getDbKey() ),
2114                                 $fname );
2115                         while( $row = $dbw->fetchObject( $res ) ) {
2116                                 $toucharr[] = $row->cl_from;
2117                         }
2118                         $dbw->freeResult( $res );
2119                 }
2120
2121                 if (!count($toucharr))
2122                         return;
2123                 $dbw->update( 'page', /* SET */ array( 'page_touched' => $dbw->timestamp() ),
2124                                                         /* WHERE */ array( 'page_id' => $toucharr ),$fname);
2125         }
2126
2127         function trackbackURL() {
2128                 global $wgTitle, $wgScriptPath, $wgServer;
2129
2130                 return "$wgServer$wgScriptPath/trackback.php?article="
2131                         . htmlspecialchars(urlencode($wgTitle->getPrefixedDBkey()));
2132         }
2133
2134         function trackbackRDF() {
2135                 $url = htmlspecialchars($this->getFullURL());
2136                 $title = htmlspecialchars($this->getText());
2137                 $tburl = $this->trackbackURL();
2138
2139                 return "
2140 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
2141          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
2142          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
2143 <rdf:Description
2144    rdf:about=\"$url\"
2145    dc:identifier=\"$url\"
2146    dc:title=\"$title\"
2147    trackback:ping=\"$tburl\" />
2148 </rdf:RDF>";
2149         }
2150 }
2151 ?>